Fluid transfer devices including a vial adapter with a pointed cannula for snap fitting on an aforesaid medicinal vessel or vial are now commonly employed for liquid drug reconstitution and administration purposes. Such devices include inter alia female vial adapters, male vial adapters, Applicant's MIXJECT® fluid transfer device, Applicant's MIX2VIAL® fluid transfer assemblage, and the like. Tears may be formed in a vial stopper during snap fitting of a fluid transfer device thereonto leading to leakage of liquid contents during injection into and aspiration from the vial. Tears also complicate liquid drug reconstitution in fluid transfer assemblages, for example, the aforesaid MIX2VIAL® fluid transfer assemblage, assisted by a negative pressure of a powder containing vial.
Tears often result from an initial inaccurate alignment between a fluid transfer device and a vial due to the latter centering the former as it snap fits thereonto such that the fluid transfer device is concentrically snap fit mounted onto the vial. Initial inaccurate alignment may be in the form of either a skewed alignment between a fluid transfer device and a vial or an eccentric alignment therebetween particularly in the case of a vial adapter with a flared skirt for assisting in guiding a vial adapter onto a vial. But tears may still occur even in the case of an initial concentric alignment between a fluid transfer device and a vial due to the constitution of an elastic vial stopper.
US Publication No. 2004/0236305 entitled Fluid Transfer Device illustrates and describes a fluid transfer device for mounting on a medicinal vessel. The fluid transfer device includes a receiving cap and a piercing mandril for piercing an elastic stopper. Relative to its direction of piercing, the piercing mandril has a front piercing portion and rear sealing portion which is of greater diameter for sealing a tear in a stopper. An alternative embodiment includes providing a rear sealing portion with a fixedly mounted elastic O-ring for providing additional sealing capability.
U.S. Pat. No. 5,374,264 entitled Universal Fitting for Inoculation Receptacles illustrates and describes a fluid transfer device for mounting on a medicinal vessel. The fluid transfer device includes a vial adapter with a top wall, a skirt and a pointed cannula provided with a sheath for folding accordion like as it is compressed between the top wall and a medicinal vessel's elastic stopper.